Place the dragon fruit on a cutting board.
Using a sharp knife, cut it in half lengthwise down the middle.
Place a large spoon in between the skin and the flesh, and slide it along the peel to separate it from the flesh.
Scoop out the flesh and place it on the cutting board. Be sure to remove all of the pink skin, which can be bitter.
Repeat with the remaining half.
Place the flesh flat-side down and chop into cubes, chunks, or semicircles.
Place the dragon fruit into a medium bowl.
Add the optional mango, pineapple, and kiwi to the bowl.
Sprinkle with lemon juice and gently toss to combine.
Serve and enjoy!